Want to remember doing something, like attending 400 lectures on molecular cell biology, without ever actually having to do it? A special kind of ultrasound can trigger neurons in your gray matter, and the team of Arizona State neuroscientists who discovered this immediately played the Total Recall card. They're already talking about implanting memories of everything from fake vacations to learning kung fu.
Ultrasound has a lot of great uses, like creating an image of an unborn baby or testing the internal structure of a piece of metal without destroying the piece. What we mean by "ultrasound" is a pressure wave with a frequency above about 20 kHz, the upper limit of hearing for most humans. By measuring the different rates of reflection off of different surfaces, we can use it as a sort of "sonic x-ray" on some materials, including pregnant women's tummies. Scientists have known for decades that ultrasound causes changes in muscle and nerve tissues, but the ASU team studied exactly what happens at the cellular level. They found that LILF ultrasound starts a series of reactions that eventually trigger synapses within the brain.
The short-term relevance of the research could revolutionize certain medical procedures that require neuron stimulation. A host of therapies for various mental conditions currently require implantation of electrodes into the brain, and thus are seldom performed due to the risk. Ultrasound might be able to do the job non-invasively and open the door to these treatments for tens of thousands of patients.
For now, the researchers are focused on giving Arnold Schwarzenegger a fake vacation to Mars. Lead investigator William Tyler weighed on the potential for ultrasonic brain control:
"One might be able to envision potential applications ranging from medical interventions to use in video gaming or the creation of artificial memories along the lines of Arnold Schwarzenegger's character in 'Total Recall.' Imagine taking a vacation without actually going anywhere? Obviously, we need to conduct further research and development, but one of the most exhilarating prospects is that low intensity, low frequency ultrasound permit deep-brain stimulation procedures without requiring exogenous proteins or surgically implanted medical devices."